docs: def extract_coverage(self, container: Container) -> FileLineSet:
          """
          Extracts a report of the lines that have been executed since the last
          time that a coverage report was extracted.
          """
          uid = container.uid
          r = self.__api.post('containers/{}/read-coverage'.format(uid))
          if r.status_code == 200:
              return FileLineSet.from_dict(r.json())
          self.__api.handle_erroneous_response(r)